AASHO road test
January 20, 2022
The AASHO Road Test is a series of field experiments conducted by the American Highway Civil Service Association (AASHO) in 1958-60 in Ottawa, Illinois. The purpose of the experiments is to "study the behavior of the road surface and structural elements of bridges under the action of moving loads of a certain magnitude and frequency." They are considered to be the first field experiments to study how cars wear out and destroy pavements and bridges. The results of the experiments were used in setting car taxes and planning road maintenance costs. The AASHO test is the most expensive in the history of construction - 27 million dollars (271 million in 2021 prices) and is considered the most ambitious road test of the twentieth century. 126 trucks and tractors with semi-trailers for 25 months and day and night, in any weather, continuously plying on test tracks. During this time, the car traveled 1,114,000 times on ring routes and covered a total of 17 million miles (27.4 million kilometers). The design of pavements and bridges for US highways is based on the results of AASHO tests, many other countries around the world have also used these results in their regulations.